Being made into the thing that kills you

I wonder if anyone's written anything on the evolution of the monster-as-contamination concept?

The Haitian zombie isn't spread through bites or disease; it's a spell cast on a person or their corpse; then again, the Hollywood zombie is really more an alternate branch of European vampire than it is a legit evolution of Haitian folklore. Werewolves in European folklore are usually attributed to curses cast on a person or deals with the devil; often, a transformative amulet like a strap of wolf-skin is involved with the latter. Vampires probably come the closest to being associated with bite-based transmission in their pre-literary, pre-filmic form, as their association with disease (victims falling ill and dying in attested cases) far predates their modern associations with sexual transgression.

In the modern euro-American popular culture, the trifecta of zombie, werewolf, and vampire are all so associated with bite-based transmission that not being spread like a disease is considered a subversion of expectations. The zombie is most often treated as literally a disease, with as much acknowledgement of magic stripped from their invocation as possible, but the werewolf and especially the vampire often invoke the symptoms and imagery of disease - the pale, white skin of the victorian-onwards vamp (as opposed to the ruddy faces of the folkloric vampire) is borrowed from victorian tuberculosis victims, the 80's and 90's slew of vampires weaving in anxieties about AIDs.

I feel like the slew of alien sci-fi monsters that assimilate flesh or parasitize hosts to reproduce also have some relationship to this trope complex...